Subjects were fed low-fat or high-mono metabolic diets in random order for 6 wk, and the 2 diets were separated by a 6-12-wk washout period. Both diets were offered at 25% above estimated energy requirement (7) to allow self-selection for quantity of food. Diets were fed by using a 4-d menu cycle. Menus for the 2 diets were similar, with the fat and carbohydrate composition changed by differences in recipes and serving sizes; subjects were thus blinded to dietary treatment, insofar as this was possible. Typical menus for the 2 diets are shown in Appendix AGo, which illustrates the manipulations of the foods that were performed to meet the low-fat and high-mono dietary prescriptions. In general, high-fat items and oils on the high-mono diet were partially replaced on the low-fat diet with fat-free oils and foods higher in complex carbohydrates.
All meals were prepared by the Metabolic Kitchen of the General Clinical Research Center at Oregon Health & Science University. Subjects consumed one meal per day at the Clinical Research Center. The other meals including the weekend meals were packaged for home consumption. Subjects were instructed to eat to satisfaction and return uneaten foods, which were weighed to allow calculation of the total energy intake and nutrient consumption by using a nutrient analysis database (FOOD PROCESSOR NUTRIENT ANALYSIS SOFTWARE, version 6.1; ESHA Research, Salem, OR; 8). Subjects were encouraged to consume their meals on a regular schedule and were instructed to maintain their usual exercise level during the study.
The low-fat diet provided 20% of energy as fat, and the high-mono diet provided 40% of energy as fat (26% of energy was monounsaturated fat; Table 3Go). The low-fat diet provided 65% of energy as carbohydrates compared with 45% as carbohydrates for the high-mono diet; refined sugar made up 10% of energy intake in both diets. The low-fat diet was higher in fiber and water content, weighed more, and had a lower energy density (kcal/g diet) than did the high-mono diet. Although both diets were low in saturated fat, the low-fat diet was lower than the high-mono diet in saturated fat and cholesterol. The difference in saturated fat and cholesterol between the 2 diets was intentional, in that we wished to study the effects of a diet in its entirety (low-fat compared with high-mono), rather than the effects of individual dietary components. A low-fat diet will generally be lower in saturated fat and cholesterol and higher in dietary fiber than will a high-mono diet, so that the composition of the 2 diets in our study likely mirrored the composition of these diets as they would be eaten in the "real world."
1. It's all processed food so they could blind which is not very good
2. they didn't even state which mono-unsats they used
3. 25% overconsumption was required
4. low fat diet had much more fiber
5. refined sugar was 10% in both diets